The invention relates to a "quiet-operating" valve construction, as for use in conjunction with throttling elements of a reducing valve. The constructions disclosed in U.S. Pat. No. 4,921,014 are illustrative of one kind of valve to which the improvement of the present invention is applicable, and therefore the disclosure of said patent is hereby incorporated by reference.
In general, it may be said that a valve suitable for use in the present invention may comprise a radially stacked succession or nesting of concentric annuli, wherein a poppet member is guided in the bore of the innermost annulus. The annuli provide successive stages of circumferentially and axially distributed radial passages, with manifolding connection of plural passages of each stage to the next-succeeding stage; and, to serve the purposes of progressive pressure reduction, the total collective sectional area increases, for the passages of each successive stage. In a pressure-reducing application, poppet position determines the volume of inlet or upstream flow to be served by some or by all of the passages of the inner annulus, and the successive stages serve progressive fractions of desired pressure reduction. Outlet or downstream flow from the valve is taken via a circumferential manifold around the outermost multiple-passage annulus.
Despite the achievements of valve constructions according to said patent, there is a need for even further noise reduction and for more ready servicing, by disassembly for periodic cleaning to assure design flow capability of the passages of all stages.